Water

Fresh, cold water, changed daily, (usually provided in a drip bottle to prevent contamination) should always be available. Avoid distilled water. Avoid water high in minerals, especially if high in calcium. Do not put vitamins or medications in the water.

Grass Hay

Unlimited high quality, grass hay (timothy and orchard grass are popular) should always be available to each and every guinea pig, no matter what age. Eating the long hay strands keeps their digestive system moving and helps prevent their teeth from over growing. It is usually placed in a wire rack off the floor for cleanliness.

Alfalfa hay can be given to young guinea pigs, pregnant, nursing or malnourished adults. But because of its high calcium content, alfalfa should be reserved as a treat for the average adult guinea pig. Excess calcium could contribute to the formation of bladder stones in older guinea pigs. Remember that alfalfa is NOT a replacement for grass hay, but can be used to supplement the diet of some pigs. Grass hay should always be available to all guinea pigs.

And remember, pellets are not a substitute for hay! High quality grass hay should be available for each guinea pig at all times.

Vegetables

Small amounts of fresh vegetables (about a cup a day) are an important additional source of vitamin C and other nutrients. Parsley, romaine lettuce (rather than iceberg, which has less nutritional value and may result in loose stools if given in excess), a small piece of carrot, tomato, green or red pepper, spinach, and cantaloupe are popular choices. And clean, pesticide-free grass, clover, dandelion greens, corn husks and silk, will be appreciated by your pet. Rinse vegetables thoroughly. Do not feed wilted or spoiled food. Vegetables must be introduced slowly, to avoid digestive upsets. Once introduced, you can supply a variety of them to your pet. Variety is the key to maintaining your pigs' health. Be creative.

Make sure that grass hay, water, and pellets (see note below) are always available (most guinea pigs will not over eat). Vegetables can be provided two or more times a day, removing uneaten vegetables to prevent spoiling.

Note: Guinea pigs prone to forming stones are sometimes fed limited or no pellets. Since pellets are a concentrated food source, be sure to review guidelines for determining if your guinea pig is a good weight. Some caretakers restrict pellet intake to 1/8 cup a day for adult guinea pigs. Other guinea pig caretakers choose to instead feed a wider variety of hays and fresh food, forgoing pellets due to medical conditions like recurring bladder stones. Ideally a nutritional analysis of a non-pellet based diet will ensure there are no vitamin nor mineral deficiencies.

Pellets *

Plain dye free high quality guinea pig pellets (mixes with nuts are considered too rich), formulated with Vitamin C can be provided in a small heavy ceramic bowl to prevent tipping and cleaned daily. Each guinea pig will eat approximately 1/8 cup of pellets a day when also fed adequate hay and fresh vegetables. Purchase pellets in small quantities and store in a dry cool dark place to preserve the potency of the C (look for a pellet with an expiration date to check for freshness). Look for a pellet that uses stabilized vitamin C and has a "Best If Used By" date to ensure quality. Avoid pellets that use animal byproducts and those whose primary ingredient is corn.

Most guinea pig pellets are alfalfa based. Alfalfa pellets are suitable for young, growing and pregnant guinea pigs. After your guinea pig is six months or more old and fully developed (more), a timothy based pellet, which provides less calcium, may be a good choice . Two quality timothy based pellets are Timothy Choice pellets by KMS Hayloft and Cavy Cuisine by the Oxbow Hay Company.

* Most guinea pig caretakers feed pellets to help meet minimum daily requirements for vitamins, minerals, and other nutrients. Some guinea pig owners choose to instead feed a wider variety of hays and fresh food, forgoing pellets due to medical conditions like recurring bladder stones. Ideally a nutritional analysis of a non-pellet based diet will ensure there are no vitamin nor mineral deficiencies.

Avoid seeds in husks (like sunflower seeds), which can be a choking hazard.

Do not feed rabbit pellets (they do not contain Vitamin C and some may even include antibiotics toxic to guinea pigs).

Avoid or use sparingly, cruciferous vegetables (cabbage, collards, bok choy, broccoli), as they may cause gas in your pet.

Do not use mineral wheels. Never use Tang (which contains dyes, refined sugars, and very little vitamin C) in drinking water.

Avoid commercial treats marketed for guinea pigs (like yoghurt drops) which can even be detrimental to their health. Consuming these empty calories (many contain fat, sugars and even excess calcium) can result in decreased consumption of the basic foods they really need.

No multivitamins!

Plain vitamin C is fine, but multivitamins are not. Excessive amounts of fat soluble vitamins like A and D can cause serious problems for your pet.